Novel flux-regulatable dual-magnet vernier memory motors for electric vehicle propulsion

In this paper, a new embranchment of memory motor entitled vernier memory motor, which artfully incorporates the flux-mnemonic concept and vernier structure, is proposed and implemented as an in-wheel motor drive for electric vehicle (EV). Two motor topologies hybridizing dual-magnet arrangement are presented, and their operating principle and design procedure are described. The ingenuity of the dual-magnet configurations is to employ the flux-modulated poles to perform large output torque in low-speed region derived from the gearing effect and to achieve an effectively flexible online flux-regulation by temporarily applying current pulses to magnetize/demagnetize the used AlNiCo permanent magnets (PM) with intrinsically low coercivity and high remanence. The electromagnetic characteristics and operation performances of the motors are analyzed and quantitatively compared by the finite-element-method (FEM), which verifies the validity of machine design.